function Cat(name,color){
    this.name = name ;
    this.color = color;
}
Cat.prototype = {
    sayMiao(){
        console.log('miao');
    }
}
var cmm = new Cat('cmm','white');
cmm.sayMiao();
console.log(cmm.__proto__==Cat.prototype);
Object.prototype.sayHello = function(){
    console.log('nihao');
}
Cat.sayHello();